STS-133: SpaceX’s DragonEye set for late installation on Discovery

July 19, 2010 by Chris Bergin

The DragonEye (DE) relative navigation sensor – set to ride with Discovery on STS-133 – will be installed two weeks later than planned, following a laser rod failure during testing. Discovery – currently enjoying a smooth processing flow – will be conducting the second test for the sensor during her arrival at the International Space Station (ISS) in November.

STS-133 Processing Latest:

Discovery is in trouble-free flow, with all of her recent processing “highlights” now at a conclusion.

See Also

As part of the re-installation of the ROMS, engineers are scheduled to perform isolation valve verification tests on the right hand OMS pod piping and test the heater and thruster for the Right Reaction Control System (RRCS) during the early part of this week’s flow.

Over the weekend, engineers connected two anhydrous ammonia bottles to the orbiter using Quick Disconnect (QD) lines to service Discovery’s ammonia boiler system. The ammonia boiler system is used on the runway prior to ground cooling and supports an emergency return and landing in the unlikely event it is needed.

This work has been previously delayed due to leaks in the associated Ground Support Equipment (GSE), which was repaired for the weekend task.

DragonEye provides three-dimensional images based on the amount of time it takes for a single laser pulse from the sensor to the reach a target and bounce back, providing range and bearing information from the Dragon spacecraft to the ISS.

At the time of its debut, the SpaceX DE was one of two leading candidates for flash Light Intensification Detection and Ranging (LIDAR) relative navigation sensor to be used on the SpaceX Dragon vehicle.

With Discovery’s STS-133 launch date also slipping, currently NET (No Earlier Than) November 1, impacts to the installation of DragonEye on to Discovery – currently slipping two weeks due to a laser rod failure – is not a problem from a processing flow standpoint.

“The Dragoneye payload was doing testing, during (which) the thermal vacuum test, there was degradation in their laser; the laser rod went all the way to failure,” noted Flight Operations and Integration (FO&I) on a recent Shuttle/Standup Integration report (L2).

“They have replaced the laser rod and are investigating the incident, but in the meantime have asked for a two week delay in their installation. This request has been worked out. The Dragoneye team is still investigating, doing some additional mitigation and retests.”

The replacement laser rod is understood to have checked out with no reported issues.